1. Field of the Invention
The present invention relates to an inkjet head and an inkjet recording apparatus, which can maintain a constant pressure in the vicinity of nozzles.
2. Description of the Related Art
For example, PCT National Pub. No. 2002-533247 discloses the following, as an inkjet head with the pressure loss improved. The inkjet head comprises nozzles, an inlet manifold, an outlet manifold, and an array of fluid chambers connected to the manifolds. The inkjet head further comprises a member for generating fluid flows running through the inlet manifold and the chambers in the array into the outlet manifold.
In the inkjet head, fluid flows running through the chambers sufficiently prevent foreign matters in the fluid from remaining in the nozzles. In the meantime, demand for such ink-circulating inkjet heads has increased as being highly-reliable inkjet heads, because of high cleanliness of ink channels thereof.
However, in ink-circulating inkjet heads, the pressure in the vicinity of nozzles varies by influence of the length of the pipes of the ink channels and the diameter of the ink channels. Further, to prevent variations in ink discharge, it is necessary to keep a constant pressure in the vicinity of the nozzles. To control the pressure in the vicinity of the nozzles to a constant value in the above conventional inkjet head, it is necessary to adjust the channel resistance of the ink channels, and adjust the pressure of the ink tank. According to these methods, high accuracy is required in adjustment of the channel resistance and adjustment of the tank pressure, and there is room for improvement.